A dream come true? (Nightmare!sans x Reader)

Your life is miserable. Lets just put it at that. Your parents died at the age of 3, your foster parents abuse you, you are ridiculed at school, and to top it off no matter what you cant get these damn nightmares to go away. So..... You end up at the large apple tree on the hill, just before 'they' get home too. You s...